Engines on commercial passenger jets are sized for take-off conditions. This design condition drives engine sizes that are larger than necessary for every other phase of the aircraft flight. The larger sized engine for take-off conditions results in higher purchase costs than would be needed otherwise to operate the aircraft. The larger engine size also results in higher cost of operation with adding weight to the aircraft, creating additional drag to the aircraft, adding fuel consumption, and affecting range of the aircraft. Eliminating this design condition and the engine mechanism to bring the aircraft to a cruise condition would improve operating efficiencies and costs.
Take-off and climb-out noise from commercial aircraft engines is a contributor to noise pollution near airports. Eliminating the design condition of the engines being sized for take-off conditions would reduce noise pollution.
At least some commercial aircraft are reliant on the onboard propulsion from the engines for take-off. An alternative to traditional commercial aircraft take-off is military aircraft use of steam or electromagnetic catapults on aircraft carriers. Another option is found in use with sailplanes. Sailplanes can be towed by a powered aircraft to launch altitude.
With respect to landing, commercial aircraft utilize thrust reversers to decelerate the aircraft. Use of thrust reversers consumes fuel and contributes to noise pollution near the airport. In addition, landing on runways imparts wear to the tires of the landing gear. In the military, aircraft carriers utilize catch line systems to decelerate the aircraft.
Airport runway sizes may be limited by geography, such as water, mountains or existing structures. Runway size may also be limited by monetary considerations or climate conditions, such as thin air. As such, some runways may not be long enough for larger aircraft to use for take-off and landing. Further, some runways may be closed to take-offs and landings due to weather conditions, such as rain or ice causing cancelled or delayed flights.